It's definitely no replacement for WAR BABY, and I don't think it was really meant to be. Riesch's little book is useful to have because it's so easy to carry to gun shows, etc.
I also have 4 and 5. I bought the 5th Edition about a year ago and it came with a small piece of paper with three small corrections I'll print below, if it's any use to someone. I wish I had known there was a 6th edition coming out! ("Oh well....)
Hooks, you really should upgrade from the 4th edition to the 6th.
(Then you can help us fix all the errors!)
Corrections
Page 44, Line 1: Barrel length should read 18 inches.
Page 84, figure 3-17: The "IP" hammer (side view only) should be on page 85 figure 3-18. The front view is correct.
Page 85, figure 3-18: The "HI" hammer (side view only) should be on page 84 figure 3-17. The front view on the right is correct.